Loud-speaker



June 17, 1930.

A. O. GOODYEAR LOUD SPEAKER Filed July 5, 1928 2 Sheets-Sheet 1 INVENTOR.

I? 0. Goodyear.

ATTORNEYS June 17, 1930. A. o. GOODYEAR 1,754,015

LOUD SPEAKER Filed July 5, 1928 2 Sheets-Sheet .2

' INVENTQR. I

FLO Good m.

A TTORNEYS Patented June 17, 1930 "UNITED STATES ADOLLPH o. GoonYEAR, OF CLEVELAND, OHIO Loon- PE KER,

. A ncaan filed July 5,

This invention appertains to the art of sounding devices wherein electrical currents are transformed into sound values throughthe medium of a Vibrating diaphragm which is caused to vibrate in accordance with a varying electrical current. These devlces are coming into extensive use in connection with radios inasmuch as it is common practice to avail of a loudspeaker together with ordinary radio receiving apparatus.

To the end of attaining to the greatest degree feasible, quality, nicety, and definition of the tone produced by the sounding device, I propose to provide a device of this character wherein a plurality of vibrating diaphragms are employed and wherein these diaphragms are maintained taut to a degree heretofore unattained inthis art. 3 In carrying out my inventive thoughts into an actual embodiment thereof, I employ a main sounding drum consisting of spaced diaphragms together with sounding postsconnecting the latter together so that they may vibrate in unison,'and in addition a secondary vibrating diaphragm which is extremely tautand which is operatively'connected with one of the first mentioned diaphragms so that vibrations of the former are transmitted to the latter through the connecting means which takes the formof so called sounding posts. By interposing the electromagnetic instrumentalities between the extremely taut diaphragm and the main sounding drum, vibrations of both are created in unison and due to the'high degree of tautness in the diaphragm spaced from the sounding drum, fineness in quality of'the tone of the sound produced is afforded.

Particular features of the invention reside in'the construction of the taut diaphragm to gether with, its mounting on the main sounding drum, notably in the means employed for obtaining the desired de 'ree of tenseness and tautness required. i

The vibrating diaphragm hereinbefore described is operatively connected with one of the diaphragms of the main sounding drum through the medium of two sounding posts which are somewhat spaced apart. Inasmuch as vibrations are transmitted by these 192s, Serial No. 290,300.

posts to a diaphragm of the sounding drum at spaced points, I have divided this diaphragm of the sounding drum into two parts so that vibrations of one may not interfere to any extent whatsoever with vibrations of the other, thereby enhancing to a still further extent, the naturalness of the tone produced. In the construction of the sounding device provided by this invention,the taut vibrat ing diaphragm is provided with members which are adapted to be influenced by electro-magnets to cause vibration of the former, the electro-magnetic instrumentalities being spaced very slightly from the member carried by the diaphragm, and these electromagnetic instrumentalities are mounted on a panel which is .carried by the sound drum, and noteworthy features of the invention lie in the mountingof this panel on the sounding drum' as well as the particular construction and arrangement of the magnetic instrumentalities. t is an object of the invention to provide means for adjusting the relationship between the panel carrying the electro-magnetic means and the sounding drum, and: to this end an! adjustable screw joinsthe lower diaphragmof the sounding drum with'the panel and thisscrew is provided with suitable operating means for causing rotation of the same to Vary the distance between these 8b parts. g

/Vith these and other objects in view as will in part become apparent and in .part be hereinafter "stated, the invention comprises certain novel constructions, arrangements, and combinations of partsas will be subsequently specified and claimed. I

For a fulland more complete'understanding of the invention, reference maybe had to the following description and accompanying drawings,-in which' v H Figure l'is a plan view of the sounding drum Witlrthe upper vibrating diaphragm, electro-magnetic instrumentalities, and its carrier panel removed therefrom.

Figure 2 is 'a bottom plan view of the instrument shown in Figure 1. v V Figure 3isa front view of the same. Figure-4 is a transverse. section taken through the entire instrument. i

described, the combination with a sounding drum, of a diaphragm spaced therefrom, means for rendering taut the diaphragm, and instrumentalities for transmitting vibrations of the diaphragm to the drum.

2'. In a sound producing instrument of the class described, the combination with a sound producing drum comprising spaced 'liaphragms, of a vibrating diaphragm spaced from the drum, means for transmitting vibration of the diaphragm to the diaphragms of the drum, and instrumentalities interposed between the drum and the spaced diaphragm for causing vibrations of both the former and latter.

3. In a sound producing device of the class described, the combination with a sounding drum and a diaphragm spaced therefrom, of

a panel carried by the drum in spaced relation thereto, means interposed between the panel and the drum for transmitting vibrations of the panel to the drum, and electromagnetic instrumentalities mounted on the panel to cause the vibration of the drum and diaphragm.

4. A sound producing instrument of the class described, comprising, in combination, a sounding drum made up of spaced diaphragms, one of said diaphragms being provided with a diametrical opening extending substantially the full distance across the same, and means for transmitting vibrations of one of the diaphragms to the other.

5. A sound producing instrument of the class described, comprising, in combination, a sounding drum, a diaphragm spaced therefrom, means for transmitting vibrations of the diaphragm to the drum, said diaphragm consisting of members joined together at their edges and spaced apart at their center to render taut the diaphragm, and means for drawing the said edges together.

6. A sound producing instrument oft-he class described, comprising, in combination, a sounding drum, a diaphragm spaced therefrom, sound transmitting posts interposed between the drum and the diaphragm at points spaced from the edges thereof, and screw members at the edges of the drum and the diaphragm for drawing said edges together against the spreading action of the sounding posts.

7 A sound producing instrument of the class described, comprising, in combination, a sounding drum made up of spaced diaphragms, a diaphragm spaced from the sounding drum, a panel carried by the sound ing drum and interposed between said drum and the spaced diaphragm, means carried by the panel for causing vibration of the diaphragm panel and drum, and connecting means for causing said vibrating motions to take place in unison.

8. In a sound producing instrument of the class described, in combination with vibrating instrumentalities of a diaphragm, said diaphragm being made up of members going together at points on their peripheries, and having means for spacing them apart at the middle thereof whereby they are rendered taut to a high degree.

9. In a sound producing instrument of the class described, the combination with electric vibrating instrumentalities, of a vibrating diaphragm, said diaphragm comprising wooden panels which engage one another at points along their edges, means for maintaining said engagement of the panels at said points, and means spaced inwardly from the edges of the panels for stretching the same apart and thereby rendering the diaphragm taut.

10. A sound producing instrument of the class described comprising, in combination, a sounding drum made up of spaced diaphragms, one of said diaphragms having a slot extending diametrically thereof, another diaphragm carried by the said slotted drum diaphragm and spaced therefrom, vibrating instrumentalities carried by the said slotted drum diaphragm whereby to efiect vibrations in the portions of the said diaphragm on each side of the slot independently of each other, and adjusting means for the said vibrating instrumentalities.

In testimony whereof I affiX my signature.

ADOLPH O. GOODYEAR. 

